LGA 771 to 775 Adapter (MOD) – Run faster Xeon CPUs in a Core 2 Quad motherboard

MODs

2,327 Comments

If you're looking to extend the life of your LGA 775 system, there's an adapter available now that will let you install faster (and usually cheaper) Intel Xeon processors (LGA 771) into a Core 2 Quad motherboard (LGA 775). These Xeons cost a lot less and are basically identical internally to the high-end Core 2 Quad CPUs.

List of LGA 771 & 775 CPUs + Current Prices

The pages shown below should help with comparing Xeon prices and specifications. The first link has all the LGA 771 and LGA 775 CPUs combined into 1 table (sorted by price), and the others are the original uncombined pages.

Where can I get an adapter?

Here's a current list of eBay sellers (sorted by price). The sellers are located all over the world, so you should be able to find one that's close to you, and most of them will also ship worldwide.

Why would you want to do this?

Xeons are usually MUCH cheaper

For example, the Xeon E5450 is equivalent to a 3.0 GHz Core 2 Quad Q9650, and it currently costs about $6 on eBay (usually much less than the Q9650).

Other good deals on LGA 771 Xeons include:

For detailed specs on all of the Xeons and a full list of current prices, take a look at this page.

Xeons also typically overclock better

Additionally, if you’re interested in overclocking (making the cpu go faster than its default speed), Xeon processors are usually made from the best silicon, so you can typically achieve higher overclocks with them.

Someone that recently did this mod successfully overclocked a Xeon X5470 from 3.33 GHz to 4.5 GHz on an ASUS P5Q PRO motherboard, so you can achieve really good results with these Xeons.

How does the adapter work?

The adapter is basically an electronic circuit on a sticker, and you place it on the Xeon processor (as shown in the picture below). This switches two of the pads on the bottom of the Xeon to make it compatible with a Core 2 Quad motherboard.

Xeons that are compatible with this adapter

This adapter is only compatible with LGA 771 Xeon processors. If you're unsure what LGA 771 means, it's the name of the CPU socket used in some Xeon motherboards. And in comparison, LGA 775 is the name of the socket used in Core 2 Duo/Quad motherboards.

LGA 771 to 775 Adapter

Minor modification to the LGA 775 socket is also required

If you look at the LGA 775 socket in the picture below, you'll notice two tabs are circled in red. These tabs are there to stop you from installing a non-LGA 775 processor, and they'll need to be fully removed before you can install an LGA 771 cpu.

The tabs are pretty easy to remove if you have a sharp utility knife or box cutter (just be careful not to damage or bend any of the socket pins near the tabs).

Important: Make sure that you fully cut off each of these tabs. If they're not fully cut off, the processor may not align or seat correctly in the socket, which will stop it from making contact with all of the pins. If this happens, your system will likely fail to boot.

Once the tabs are cut off, you can use tweezers to safely remove the pieces from the socket.

The socket will then support LGA 771 or 775 processors (you can still reinstall your old processor if you ever need to).

Tabs to removed from the LGA 775 socket

2,327 Responses

  • ph4nt0m August 25, 20197:12 am

    ABIT AB9 QuadGT (P965 / ICH8R) with the latest v18 beta BIOS that supports E0 CPUs. Works great with L5408 E0 SLBBT 2.13GHz oc’ed to 3.2GHz at 1.12V (1600MHz FSB). 1333MHz FSB CPUs may need a BSEL mod to 1066MHz FSB in order to boot up. They can be clocked back in the BIOS.

    Reply
    • Rati Daraselia October 1, 201912:44 pm

      Does Asus P5G41T-M-LX2/GB Motherboard with latest 0504 BIOS works with modded Xeon E5450 CPU? Help me please
      p.s it works with Xeon e5450 equivalent LGA 775 C2Q Q9650 CPU..
      Motherboard chipset – G41/ICH7
      FSB Speed – 1333/../…

      Reply
  • SAURHOS September 7, 201910:39 am

    HELLO , I’M TRYING TO RUN A XEON X5472 C0(SLASA) ,IN A GIGABYTE GA- EP45T-UD3LR REV. 1.1 AND OTHER ONE REV. 1.3, BUT NOT WORKING WELL.
    IN THE MOTHER REV 1.1 :NOT ACCEPTING MEMORIES IN DUAL CHANNEL, ONLY 2 MODULES OF 4G 1600MZ , IN SINGLE MODE , LIMITING HALF CAPACITY. SO I UPDATED THE BIOS TO VERSIONS: F8, F9, F10 AND F12 ​​VERSIONS, AFTER NO SUCCESS, THEN I MADE A MOD BIOS WITH F12 VERSION BY METHOD 1 REPLACING ALL MICROCODES 45nm AND 65nm, BUT I WAS NOT SUCCESSFUL, STILL NOT RUNNING WITH THE 4 MEMORIES MODULES.
    ON THE MOTHER REV 1.3 DID NOT UPDATE THE BIOS, AND IS WITH THE (F8) VERSION AND IT RUNS IN DUAL CHANNEL, WITH THE 4 MEMORIES MODULES AT 1600MHZ BUT, IT ONLY RECOGNIZES THEM AFTER BUZZER BEEP 20 TIMES OR MORE, EVEN REBOOTING IT A FEL TIMES.AT ONCE OF THIS REBOOTING ,I RECEIVE A MESSAGE :(POST error occurs ! )WITH A BACKGROUND COUNT, FOLLOWING TO( LAST KNOWN GOOD )IF I DON’T TOUCH ANYTHING.SO ONE TIME I GET INTO THE SETUP AND CONFIGURE THE CMOS , WITH SIMPLE THINGS, LIKE, UPDATE THE TIME AND DATE, DISABILITY THE FLOPPY , ORDER THE BOOT SEQUENCE, ……I THINK THIS WAS ALL, AND AFTER THIS ,IT NOT RUN IN DUAL CHANNEL ANYMORE , JUST WITH 2 MODULES IN SINGLE CHANNEL,THEN AFTER THIS I MADE A RESET ON CMOS, IN THE PINS AND AFTER 20 BUZZER BEEPS, THE MOTHER RECOGNIZED THE MEMORIES AND STARTED WITH THE 4 MODULES AGAIN.
    NOTE: AT THE TWO MOTHERBOARDS ,THERE IS NOT ANY MESSAGE IN THE POST SCREEN “ASKING TO UPDATE THE BIOS TO HAVE TOTAL PROCESSOR FUNCTIONALITY ” LIKE I SAW PEOPLE SAYING ON WEB.
    I SAW THIS MOTHER IS BETWEEN THE LIST THAT YOU TESTED, BUT THE XEON X5472 IS NOT BETWEEN THE PROCESSORS THAT YOU USE ON IT, SO MY QUESTION IS:
    HE WAS NOT TESTED ON IT MOTHER ?
    OR IT WAS TESTED AND DOES NOT WORK ?
    OR THERE IS ANY REASON WY IT WON’T WORK ?
    CAN YOU GIVE ME SOME SUPPORT ABOUT THIS?
    NOTE: I USED A CORE 2 QUAD Q9550 AND IT WORK NORMAL WITHOUT ANY ISSUE AND MY OS IS WINDOWS 7 64BITS.
    SINCE I’M VERY THANK YOU FOR YOUR HELP.

    Reply
  • not_bill September 14, 20192:41 pm

    fyi: L5420 workung fine with ASUS P5NT WS

    Reply
  • nixon September 19, 20194:04 pm

    do you think this would work with something like a dell optiplex 780?

    Reply
  • Luiz Otavio Moreira September 22, 201910:02 am

    Motherboard ASUS P5E-VM HDMI working perfectly with processor E5450.

    Reply
  • barbar September 25, 201910:25 am

    GA-EP35-DS3 rev.2.1 works with Intel Xeon E5450 SLBBM (E0 stepping). However, modding bios F4 was needed, and of course system reinstall

    Reply
  • Wouter Verbruggen September 29, 20198:31 am

    ASUS P5N32-E SLI very unstable with 45nm quads. Tested with E5450 E0, X3363 E0 and E5420 C0, on a modded bios

    Reply
  • MVA October 4, 201912:49 pm

    Dell Studio 540 (M017G motherboard) -> With Xeon e54050

    With original bios (v1.1.3). Processor recognized, and correct speed. But not accept 64Bit instructions and problem with cpu temp detection -> Full fun speed, but work perfect.

    I modded the bios, adding microcodes, Recognized all instruccions and run Windows 10 64Bits, perfectly, with perfect recognized of cpu temp (now fun run at normal speed).

    Perfect working station with windows 10 64bits, virtual machines… etc… run Fortnite, NFS Shift… and others. (Radeon HD6570)

    Reply
    • MVA October 4, 201912:49 pm

      E5450 E0 ….

      Reply
  • саша October 4, 20192:36 pm

    я не нашол свою материнскую плату ECS P4M900T-M

    Reply
  • maxi_v8 October 4, 20195:10 pm

    hi , i have Xeon x5470 3.33GHz working fine with Asus P5K-SE-EPU , BIOS 0501 mod with microcode like expplain this forum.

    Temps are hot with the stock cooler from intel core2duo e7200 , i get 50-60 ºC, even around 70ºC on full load and cooler ~2500 RPM

    Reply

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Problem with this MOD? Please read the troubleshooting section before reporting a problem. If that doesn't help, please tell us all of the things you've already tried.

Unsure about compatibility? Please read the motherboard compatibility and tested motherboards sections of this guide.